arm64: perf: Add support caps under sysfs

ARMv8.4-PMU introduces the PMMIR_EL1 registers and some new PMU events,
like STALL_SLOT etc, are related to it. Let's add a caps directory to
/sys/bus/event_source/devices/armv8_pmuv3_0/ and support slots from
PMMIR_EL1 registers in this entry. The user programs can get the slots
from sysfs directly.

/sys/bus/event_source/devices/armv8_pmuv3_0/caps/slots is exposed
under sysfs. Both ARMv8.4-PMU and STALL_SLOT event are implemented,
it returns the slots from PMMIR_EL1, otherwise it will return 0.

Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/1600754025-53535-1-git-send-email-zhangshaokun@hisilicon.com
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Shaokun Zhang
2020-09-22 13:53:45 +08:00
committed by Will Deacon
parent 688494a407
commit f5be3a61fd
4 changed files with 78 additions and 33 deletions

View File

@@ -73,6 +73,7 @@ enum armpmu_attr_groups {
ARMPMU_ATTR_GROUP_COMMON,
ARMPMU_ATTR_GROUP_EVENTS,
ARMPMU_ATTR_GROUP_FORMATS,
ARMPMU_ATTR_GROUP_CAPS,
ARMPMU_NR_ATTR_GROUPS
};
@@ -109,6 +110,8 @@ struct arm_pmu {
struct notifier_block cpu_pm_nb;
/* the attr_groups array must be NULL-terminated */
const struct attribute_group *attr_groups[ARMPMU_NR_ATTR_GROUPS + 1];
/* store the PMMIR_EL1 to expose slots */
u64 reg_pmmir;
/* Only to be used by ACPI probing code */
unsigned long acpi_cpuid;